1. Field of the Invention
This invention relates to an improvement in a fluid coking process.
2. Description of Information Disclosures
Fluid coking is a well known process which may be carried out with or without recycle of the heavier portions of the fluid coking zone effluent. As is well known in the art, the fluid coking process, as shown, for example, in U.S. Pat. No. 2,881,130, which is hereby incorporated by reference, uses a fluid coking vessel and an external heating vessel. A fluid bed of solids, preferably coke particles produced by the process having a size in the range from about 40 to about 1000 microns is contained in the coking zone by the upward passage of fluidizing gas, usually steam, injected at a superficial velocity usually between 0.3 and 5 feet/sec. The temperature in the fluid coking bed is maintained in the range of 850.degree. to about 1,400.degree. F., preferably between 900.degree. and 1,200.degree. F. by circulating solids (coke) to the heating vessel and back. The heavy oil to be converted is injected into the fluid bed and upon contact with the hot solid undergoes pyrolysis evolving lighter hydrocarbon products in vapor phase, including normally liquid hydrocarbons and depositing a carbonaceous residue (coke) on the solids. The turbulence of the fluid bed normally results in substantially isothermal reaction conditions and thorough and rapid distribution of the heavy injected oil. The feed rate and temperature are controlled to maintain the bed in a fluidized state. Product vapors, after removal of entrained solids, are withdrawn overhead from the coking zone and sent to a scrubber and fractionator for cooling and separation.
U.S. Pat. No. 3,206,392 discloses a fluid coking process in which a stream of coke is removed from the burner and passed to a quench elutriator to separate and cool the larger coke particles from the smaller coke particles.
U.S. Pat. No. 4,118,281 discloses recycling organic waste to a fluid coker. The organic waste and coker feed oil are first heated to form a pitch-like composition that is charged to the coker.
U.S. Pat. No. 3,917,564 discloses adding sludge and other organic industrial wastes to a delayed coker as an aqueous quench medium. The water content of the sludge is utilized to cool the coke.
It has now been found that utilizing an aqueous industrial sludge containing organic wastes as quench medium in the elutriation zone produces an effluent having an increased fuel value due to the presence of the volatilzed organic materials derived from the solid organic waste.